Assignment_2_Richter_Dominic

Assignment 2 – GPS App and conclusion during its use
After installing the GPS Application, which is named “GPSTest”, the first menu bar was about the
general status of each individual GNSS satellite which was in view of the receiving smartphone at this
time. In figure 1 the list of those satellites can be seen.
Beneath some data of the reciever like the local coordinates
or the moving speed, the most important thing to see in this
list are the huge amount of all visible satellites, their
identification number, their frequency bandwith they are
transmitting and the signal to noise ratio of each of them.
The first interesting finding was that not all recievers could
see all the different satellites from the countries which
operate them. This depends mainly on the age of the
implemented GPS chip and of course on the hardware itself.
Furthermore the signal to noise ratio “C/NO” named in the
table depended mostly on the position of the reciever and
the speed it is moving. That means that the signal to noise
ratio droped dramatically while the reciever was moving or
standing beneath a wall.
The different average SNR will be showen here:
• In Buildings: 0dB
• Under metal container: ~20dB
• Near a wall: ~25dB
• Near the FH building: ~30dB
• Open field: ~40dB
Figure 1 Status bar of visible satellites
When switching to the menu bar “Sky” I could see all the listed satellites
from before and their distribution. These can be seen in figure 2. While
looking at the legend, which is shown in figure 3, it
can be seen, that not all visible satellites are in use
for the device and some of them are even not in
the view of it. Depending on the exact location, the
number of the visible satellites varied between 10
and 32 and the average accuracy was only
depending on the movement on the receiver. While
I was standing still the horizontal accuracy was
about 1.5m and the vertical 9m. But while moving
with approximately 1.5m/s the accuracy dropped to
5m horizontally and about 17m for the vertical
component.
The different shapes of the satellites seen in figure
2 are the identification of the operating country.
Figure 3 Satellite distribution on the Sky
Figure 2 Legend of Sky Menu bar
Dominic Richter MatrNr: 51853396 12.10.2022